This article about the magical qualities of semen is about to give many a douchey dude new fodder. Still, there are some fascinating tidbits.

Jesse Bering, everyone's favorite evolution-of-dicks specialist, takes a look at the body of research on semen for his Scientific American blog. There aren't any new studies here, but there are several that have been overlooked or forgotten.

It all started when two scholars noticed data suggesting lesbians' periods don't sync like heterosexual women's have been shown to do, which led them to wonder whether semen made the difference. It turns out almost no one studied the effects of semen on a woman's body. Weird, says Bering, because vaginas are so absorptive and semen is so, well, rich, at least as he describes it:

Perhaps the most striking of these compounds is the bundle of mood-enhancing chemicals in semen. There is good in this goo. Such anxiolytic chemicals include, but are by no means limited to, cortisol (known to increase affection), estrone (which elevates mood), prolactin (a natural antidepressant), oxytocin (also elevates mood), thyrotropin-releasing hormone (another antidepressant), melatonin (a sleep-inducing agent) and even serotonin (perhaps the most well-known antidepressant neurotransmitter).

Sentences like "there is good in this goo" are why Bering has a blog in addition to a Ph.D., and also why it's hard to keep a straight face while reading, no matter how peer-reviewed the studies might be. Still, listen to this. A survey of 293 college women published in 2002 found the following:

Even after adjusting for frequency of sexual intercourse, women who engaged in sex and "never" used condoms showed significantly fewer depressive symptoms than did those who "usually" or "always" used condoms. Importantly, these chronically condomless, sexually active women also evidenced fewer depressive symptoms than did those who abstained from sex altogether. By contrast, sexually active women, even really promiscuous ones, who used condoms were just as depressed as those practicing total abstinence.

Bering combs the literature on gay men having unprotected sex and finds some interviewed gay men saying they felt a sense of "connectedness" when not using condoms, which is about the best that can be mustered right now. He also throws in the Papua New Guinea tribes where pre-pubescent boys fellate older men because sperm is said to confer manliness.

Also, lesbians, you're shit out of luck, at least according to this preliminary research.

There is, of course, a giant risk in even talking about it, and that is making unprotected sex have an added benefit beyond the proverbial "it feels better," and Bering acknowledges it.

Sperm also has a rather creepy quality for those uninterested in immediate reproduction: It's so determined to get a woman pregnant that it apparently contains female hormones designed to prime ovulation in a woman even when she's not on cycle:

As a counterdefense against women's concealed ovulation, male evolution had a trick up its sleeve, which was the ability to manipulate the timing of a woman's ovulation to suit his own insemination schedule—that is to say, semen chemistry seems to give premature eggs a nice little nudging. Hence the conspicuous presence of FSH (which causes an egg in the ovary to ripen and mature) and LH (which triggers ovulation and release of that egg).